Srinagar , India -LRB- CNN -RRB- -- An Indian army trooper gunned down two of his colleagues with his service rifle in the frontier Poonch district of Indian-administered Kashmir on Sunday before turning the gun on himself .

`` Senior army officers have rushed to the spot to investigate , '' an Indian defense spokesman said .

`` The army has also ordered a court of inquiry to ascertain the facts , '' defense spokesman Col. Manish Mehta told CNN .

This is the second fratricidal incident in Indian-administered Kashmir this year . In February , five troopers were shot dead by a colleague before he killed himself .

Senior security force officers attribute the problem to stress because of long duty hours .

Several remedial measures -- including granting periodic leaves , bringing in counselors and providing recreational facilities -- have been put in place .

Kashmir is a mountainous region that has long been the subject of dispute between India and Pakistan . Both sides keep large numbers of troops in the region .

Since 1989 , India has also been fighting against a violent separatist movement in the mainly Muslim area it controls , a conflict that has killed tens of thousands of people .

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Indian army trooper uses service rifle to kill fellow troopers and himself

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The incident took place in the Poonch district of Indian-administered Kashmir

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In a similar incident in February , a trooper shot five colleagues and himself